lib/python/Components/Sources/Boolean.py

   1 from Source import Source
   2 from Components.Element import cached
   3 from enigma import eTimer
   4
   5 # a small warning:
   6 # you can use that boolean well to express screen-private
   7 # conditional expressions.
   8 #
   9 # however, if you think that there is ANY interest that another
  10 # screen could use your expression, please put your calculation
  11 # into a seperate Source, providing a "boolean"-property.
  12 class Boolean(Source, object):
  13         def __init__(self, fixed = False, function = None, destroy = None, poll = 0):
  14                 Source.__init__(self)
  15                 self.function = function
  16                 self.fixed = fixed
  17                 self.post_destroy = destroy
  18                 if poll > 0:
  19                         self.poll_timer = eTimer()
  20                         self.poll_timer.callback.append(self.poll)
  21                         self.poll_timer.start(poll)
  22                 else:
  23                         self.poll_timer = None
  24
  25         @cached
  26         def getBoolean(self):
  27                 if self.function is not None:
  28                         return self.function()
  29                 else:
  30                         return self.fixed
  31
  32         def setBoolean(self, value):
  33                 assert self.function is None
  34                 self.fixed = value
  35                 self.poll()
  36
  37         boolean = property(getBoolean, setBoolean)
  38
  39         def poll(self):
  40                 self.changed((self.CHANGED_ALL,))
  41
  42         def destroy(self):
  43                 if self.poll_timer:
  44                         self.poll_timer.callback.remove(self.poll)
  45                 if self.post_destroy is not None:
  46                         self.fixed = self.post_destroy
  47                         self.poll()
  48                 Source.destroy(self)